Fault supervision functions of the transmission apparatus include a process of periodically inspecting various faults of the transmission apparatus, managing fault generation and changes in recovery states, notifying the fault generation and the recovery and the like. When a unit fault or a line fault is detected by a hardware of the transmission apparatus, an input/output (I/O) map is formed in the I/O memory based on data output from the hardware. This I/O map indicates the fault/recovery state in real-time. A software of the transmission apparatus notifies the fault generation at each supervision point based on the I/O map to a maintenance person by turning ON a light emitting element or the like, or to a host apparatus. In addition, the software of the transmission apparatus also notifies state change information related to the fault/recovery state.
The notification of the state change information related to the fault/recovery state is carried out by a method called a change of status (COS) process which detects whether or not the same supervision state continues and detects the change related to the fault generation.
However, recently, the number of supervision items has increased considerably in order to realize an improved service of a fault supervision system of the transmission apparatus, and the tendency is that there are varieties of related processes. For this reason, it is becoming necessary to carry out a large number of complex processes within a short time, and there are increasing demands to realize a high-speed fault supervision process.